This time it is a massive Blue Whale that floated onto a Pescadero beach in San Mateo County.

Jim Aswauld, with the Marine Mammal Center, said they got word of the whale on Sunday and have been studying it ever since.

Aswauld said it is an 80-foot 75-ton Blue Whale that was pregnant at the time of her death. A male fetus is now about 50 feet from the larger carcass. Someone from the Long Marine Lab in Santa Cruz told the San Jose Mercury News that the the fetus was probably discharged post-mortem from a discharge of gas pressure.

Blue Whales are rare in the Bay Area. The last time one landed on a Bay Area beach was in 1979.

Researchers don't know how the whale died, but think it happened within the last week.

This is the normal migration time for whales along the California coast. They are heading to Baja for winter. Blue whales are the largest animals in the world. They can grow to 110 feet and weigh up to 180 tons.